Raman Spectroscopy Detects Biochemical Changes Due to Different Cell Culture Environments in Live Cells In Vitro

The in vitro cell culture environment can impact on cell biochemistry and cell cycle. The manifestation of such substrate-induced changes in cell cycle in the Raman microspectroscopic profiles of cell cultures is investigated at the level of nucleolus, nucleus and cytoplasm. HeLa immortalised human cervical cells and HaCaT dermal cells were cultured on three different substrates, conventional polystyrene cell culture dishes, CaF2 slides as a commonly used Raman substrate, and glass slides coated with collagen rat tail, as a mimic of the extra-cellular matrix (ECM) environment. A cell cycle study, based on percentage DNA content, as determined using propidium iodide staining and monitored by flow cytometry, was performed on cells of both types, grown on the different substrates, confirming that the in vitro cell culture environment impacts significantly on the cell cycle. Live cell in vitro Raman spectroscopic analysis of cells on the 2D CaF2 and 3D collagen substrates was performed and data was analysed using principal component analysis (PCA). The spectroscopic analysis revealed differences in profiles which reflect the differences in cell cycle for both in vitro culture environments. In particular, the Raman spectra of cells grown on CaF2 show indicators of cell stress, which are also associated with cell cycle arrest at the G0/G1 phase. This work contributes to the field of Raman spectroscopic analysis by providing a fresh look at the significance of the effect of in vitro culture environment to cell cycle and the sensitivity of Raman spectroscopy to such differences in cell metabolism

Comparison of time-gated surface-enhanced raman spectroscopy (TG-SERS) and classical SERS based monitoring of Escherichia coli cultivation samples

The application of Raman spectroscopy as a monitoring technique for bioprocesses is severely limited by a large background signal originating from fluorescing compounds in the culture media. Here, we compare time-gated Raman (TG-Raman)-, continuous wave NIR-process Raman (NIR-Raman), and continuous wave micro-Raman (micro-Raman) approaches in combination with surface enhanced Raman spectroscopy (SERS) for their potential to overcome this limit. For that purpose, we monitored metabolite concentrations of Escherichia coli bioreactor cultivations in cell-free supernatant samples. We investigated concentration transients of glucose, acetate, AMP, and cAMP at alternating substrate availability, from deficiency to excess. Raman and SERS signals were compared to off-line metabolite analysis of carbohydrates, carboxylic acids, and nucleotides. Results demonstrate that SERS, in almost all cases, led to a higher number of identifiable signals and better resolved spectra. Spectra derived from the TG-Raman were comparable to those of micro-Raman resulting in well-discernable Raman peaks, which allowed for the identification of a higher number of compounds. In contrast, NIR-Raman provided a superior performance for the quantitative evaluation of analytes, both with and without SERS nanoparticles when using multivariate data analysis. (c) 2018 American Institute of Chemical EngineersPeer reviewe

Hybrid EEFIT mission to february 2023 Kahramanmaraş earthquake sequence

The southwestern part of Türkiye was hit on 6 February 2023 by an Mw 7.8 (epicentre:Pazarcık) and then an Mw 7.5 earthquake (epicentre: Elbistan). The event was followed by tensof thousands of aftershocks including the Mw 6.3 event on 20 February (epicentre: Uzunbağ).This paper reports on the preliminary findings of the mission organised by the UK’s EarthquakeEngineering Field Investigation Team (EEFIT) to the Kahramanmaraş Earthquake sequence ofFebruary 2023. This mission followed a hybrid model, combining field and remote investigationtechniques, to investigate the characteristics of the earthquake sequence, its impact on buildingsand infrastructure, as well as the efficacy of relief, response and recovery operations. The keymessages include that the building stock is hard to categorise which brings along difficulties withdamage assessment, that the recovery and reconstruction require multi-sectoral engagement ofkey stakeholders, and that the auditing and quality control mechanisms within the constructionindustry need revisiting in the way forward for better disaster resilience in Türkiye

Papillon-Lefevre syndrome - Analysis of peripheral blood lymphocyte subsets

We have studied the peripheral blood lymphocyte populations in our 6 patients (2 female and 4 male) with a mean age of 11.19 with Papillon-Lefevre Syndrome (PLS) using adequate monoclonal antibodies and double coloured flow cytometry. Total B, T, CD4, CD8, CD29, CD45RA, NK, HLA-DR cells were studied. Total B, T, CD4 and CD8 lymphocytes were within normal limits. We have observed an increase in the CD29 lymphocytes and NK cells and a decrease in CD45RA lymphocytes. We think that these findings are important in explaining B lymphocyte activation and in the pathogenesis of the PLS

Papillon-Lefevre syndrome. Analysis of neutrophil chemotaxis

PAPILLON-LEFEVRE SYNDROME (PLS) IS DESCRIBED as the association of palmar-plantar hyperkeratosis with precocious periodontal disease which results in exfoliation of primary and permanent dentitions. This study was planned to assess the chemotaxis of peripheral blood neutrophils in 7 patients (3 females and 4 males) with Papillon-Lefevre syndrome. The neutrophil chemotaxis was analyzed using the zymosan activated serum (ZAS) assay. Chemotaxis and spontaneous migration measurements were compared to those of the healthy control subjects. The peripheral blood neutrophil chemotaxis and spontaneous migration were depressed in all patients with Papillon-Lefevre syndrome. The decreased chemotaxis of peripheral blood neutrophils strongly suggests that the neutrophils may act as one of the important key determinants in the pathogenesis of severe periodontal destruction in patients with PLS